Shock absorber



c. SAURER 2,069,049

SHOCK ABSORBER Filed oci. 14, 1935 2 Sheets-Sheet 1 Jan. 26, 1937.

. INVENTOR w E N R O w W A Y n- 7 c. SAURER SHOCK ABSORBER Filed Oct.14, 1933 2 Sheets-Sheet 2V INVENTO R Gufl' Samver ATTO RNEYS PatentedJan. 26, 1937 UNITED STATES sHocK ABSORBER Curt Saurer, Akron, Ohio,assignor to The Firestone Tire & Rubber Company, Akron, Ohio,

a corporation of Ohio Application ctober 14, 1933, Serial No. 693,632

7 Claims.

This invention relates to so-called shock absorbers or vibration damperssuch as are used, for example, on motor vehicles, and more especially itrelates to shock absorbing devices em- .ploying both mechanical andhydraulic means for cushioning and abating the bound and rebound of thevehicle.

The chief objects of the invention are to check the bound and rebound ofa vehicle with the same smoothness of operation; to provide the securityand positive action of a mechanical shock absorber with the smoothnessof operation of a hydraulic shock absorber; to provide, in a shockabsorber improved means for cushioning the initial impact; and toprovide a combination mechanical and hydraulic shock absorber whereinone of the shock absorbing elements cooperates with the other element incushioning and damping shocks and vibration.

Of the accompanying drawings Figure 1 is an elevation of onei pmbodimentof the invention in its application to a motor vehicle; 7

Figure 2 is a section on the line 2-2 of Fig- Figure 3 is a sectioncit-the line 3-3 of Figure 2;

Figure 4 is an elevation of another embodiment of the invention appliedto a motor vehicle;

Figure 5 is a section on the line 55 of Figure 4; and

Figure 6 is a section on the line B6 of Figure 5.

Referring to Figures 1 to -3 of the drawings,

the improved shock absorber, generally designated l0, comprises ahousing composed of two mating, metallic shells of which the rear shellIlla is formed with suitable square bolt holes II, I I by which thestructure may be mounted, as on the vehicle frame l2, by means ofrespective square-shouldered bolts I3, the heads of the latter beingdisposed interiorly of the housing. The margin of the shell Illa isformed with an ofiset flange l4 that is telescoped with the marginal 5portion of the front shell "lb of the housing, said shells beingpermanently joined together as by welding to effect a fluid-tightjuncture. In plan the housing is of general sector shape, having anarcuate lateral face that is concentric about an axis that is disposedwithin the housing structure.

At said axis the rear shell Illa is formed with an outwardly extending,cup-shaped formation I5 that constitutes a'journal bearing for one end55 of a shaft I6 that is disposed interiorly of the housing. The saidshaft extends through a suitable axial aperture in the front shell Illb,which aperture is formed with an annular flange 11 constituting ajournal bearing for the front end of said shaft, the latter beingperipherally grooved 5 at two points I8, 18 to accommodate suitablepacking I9. Clamped upon the front end of the shaft I 6, exteriorly ofthe housing I0, is a lever arm 20, said lever arm being restrainedagainst axial displacement by a washer 2|, and a bolt 10 22 that isthreaded into the outer end of said shaft. The free end of lever arm 20is pivotally connected to one end of'a link 23 that is pivotallyconnected at its other end to a fixture or bracket 24 that is mountedupon a spring-pad 15 of a vehicle axle 25. The arrangement is such thatrelative movement of the vehicle frame 12 and axle 25, due to bound orrebound, will be transmitted through the link 23 and lever arm 20 to theshaft 16 to cause angular movement or 20 rocking of the latter.

Permanently fixed upon the shaft l6, within the housing In, is a radialvane or piston 21 that is of general-rectangular shape and has itsmargins slightly spaced from the housing wall at 25 all points. Thefront, rear, and free marginal portions of the piston 21 are formed withrespective flanges 28 that project laterally on both sides of thepiston. In the normal position of the device the piston 21 is disposedvertically, 30 midway between the opposite sidewalls of the housing, asis most clearly shown in Figure 3.

Mounted within the housing I, in snug engagement with the oppositelateral faces of the piston 21 and the respective end walls of the 35housing, are respective shock absorbing bodies or cushions 29, 29 ofresilient rubber composition. The said cushions are so arranged as to besubjected to compressive force alternatively as a the piston 21 isoscillated one way or the other 40 by rocking of the shaft I6, whichforce they yieldingly resist. The thickness of the cushions 29- is suchthat they are spaced from the front and rear walls of the housing,'theflanges 28 on the piston 21 serving to keep them in proper position. Thetop and bottom faces of the cushions preferably are somewhat concave asshown, the arrangement being such as to provide space for thedisplacement of the rubber of the cush ions, within the housing, whensaid cushions are placed under pressure.

The space within the housing l0 not otherwise occupied by the piston andcushions is filled with fluid 30 that preferably is non-freezing andnoncorrosive so as not deleteriously to affect the 56 metal or rubber.Such a fluid may be a glycerin composition. The fluid is introduced intothe housing after assembly through a duct 3| formed in the shaft [6, thebolt 22 being threaded into the outer end of the duct to provide aclosure for the same.

In the operation of the device, oscillating movement of the piston ineither direction is yieldingly resisted by the fluid and by thecushions. The space between the margins of the piston 21 and the housingwall is so small that the fluid passes to the opposite side of thepiston in a small stream whereby the movement of the piston is retarded.This action is immediate upon any movement of the piston and serves tocushion the initial shock of bound or rebound of the vehicle, beforeeither cushion 29 is appreciably deformed. The cushions supplement theretardirrg action of the fluid, and, because of their progressivelyincreasing resistance to deformation, serve to slow down and, ultimatelyto limit the movement of the piston. The displacement of the rubber ofcushions 29 when under pressure also serves to increase the pressure ofthe fluid on that side of the piston whereby the retarding ability ofthe fluid is amplified. Thepresence of the fluid in a shock absorberemploying rubber as a cushioning means is advantageous in that theresistance of the fluid serves as a check against the expansive force ofthe deformed cushion, with the result that rebound is retarded andlargely checked before the piston moves past center into engagement withthe other cushion.

Referring now to Figures 4 to 6 of the drawings, there is shown thereinan embodiment of the invention that operates on the same principles asthe device hereinbefore described, but is of somewhat modifiedconstruction. The modified structure comprises a hollow, cylindricalhousing 35 consisting of an upper shell 35a and a lower shell 35b, saidshells being substantially of the same size and formed with respectivemarginal flanges 36, 36 whereby they may be joined together in afluid-tight seam as by the use of bolts 31, 31.

The end wall of lower shell 35b is exteriorly 'formed with an aperturedlug 38 by which the housing is pivotally mounted upon a shouldered bolt39 carried by a bracket 49 that is mounted upon the frame member l2 of avehicle. 5'- The upper shell 35 has its end wall axially apiertured andprovided with a stufling box 4! for the piston rod 42 of a piston 43within the housing, the diameter of the piston being somewhat smallerthan the inside diameter of the housing to provide a narrow annularpassage 44 about said transmitted through the link 23, lever arm 46,

and piston rod 42 to the piston 43 to cause axial .movement of thelatter in its housing. Normally the piston is centrally positionedwithin the housing as is shown in Figure 5.

Mounted upon the piston rod 42 and extending from the top of the piston43 to the upper end wall of the housing is a shock absorbing body orcushion 49 of resilient rubber composition. The periphery of the cushion49 is formed with a series of spaced circumferential ribs 50, 50 thatdefine intervening channels 5!, 5!, the outer margins of the said ribsbeing spaced slightly from the inner face of the housing. Each of theribs 50 is formed with a plurality of marginal notches orre-entrants-52, Figure 6, for a purpose presently to be described.

Interiorly the cushion 49 is formed with annular recesses or hollows 53,53 about the central aperture through which the piston rod 42 extends.Below the piston 43 is a cushion 54 that is similar in all respects tocushion 49 except that it has no axial aperture and the recesses 53 areomitted, said cushion 54 resting upon the bottom of the housing andabutting the bottom of the piston. The arrangement is such that thecushions 49, 54 are substantially of equal resilience and exert asubstantially equal resistance to deformation through axial movement ofthe piston. Space within the housing not occupied by the piston andcushions is filled with fluid, such as glycerin composition, that isadmitted to the housing through a port 55 in the top thereof.

The cushions 49, 54 and the fluid in the housing 35 supplement eachother in resisting axial movement of the piston 43, and the deformationof said cushions modifies the normal action of the fluid in the samemanner as in the other embodiment of the invention, whereby the shockabsorbing character of the device is improved and the other objects setout in the foregoing statement of objects are achieved.

The invention may be otherwise modified without departing from thespirit of the invention or the scope of the appended claims.

What is claimed is:

1. In a device of the character described, the r 2. In a device of thecharacter described, the

journaled therein, an oscillating piston on said rock shaft having itsmargins spaced from the wall of the housing, blocks of resilient rubberengaging the respective lateral faces of the piston and opposite wallsof the housing, a body of fluid occupying the remainder of the spacewithin the housing, and means for passing fluid through the rock shaftand into the housing.

4. In a device of the character described, the combination of a closedcylindrical housing, a reciprocable axial piston rod extendingthereinto, a piston on said piston rod spaced from the wall of thehousing, respective blocks of resilient rubber engaging opposite sidesof the piston and opposite endwalls of the housing, said rubber blocksbeing formed with radial flexible flanges extending substantially to thewall of the housing, said flanges being notched, and a body of liquidoccupying the remainder of the space within the housing, said flangesbeing forced into yieldable sealing engagement with the wall of thhousing by reason of the transverse expansion of the rubber blocks asthe latter are alternately compressed by the piston.

5. In a shock absorber, the combination of a closed housing, a pistontherein mounted inter-' mediate the ends of said housing and slightlyspaced from the side walls thereof, said piston being movable withinsaid housing, a liquid disposed in said housing at opposite sides ofsaid piston, and a rubber member disposed in said "housing on each sideof said piston, each of said be deformed by movement of said piston in adirection toward one end of said housing, the rubber member on one sideof said piston increasing in cross-sectional area and the rubber memberon the other side of said piston decreasing in cross-sectional area todisplace the liquid from said end of the housing to the other end ofsaid housing on the other side of said piston.

6. A shock absorber comprising a closed housing, a movable pistontherein, said piston being spaced from said housing, a pair ofdeformable rubber members disposed in said housing between said pistonand the respective ends of said housing, said deformable member being soproportioned within said housing as to provide a space between themember and said housing, a liquid medium disposed within said spaceentirely within said housing, said piston and housing being soconstructed and arranged that said member may be deformed by movement ofsaid piston as to displace said liquid from one end of said housing pastsaid piston to the other end of said housing as said rubber member istransversely expanded by reason of longitudinal compression thereof bythe piston.

7. A shock absorber comprising a closed housing, a movable piston withinsaid housing, and a deformable rubber member interposed between saidpiston and an end of the housing, said deformable rubber member beingprovided with alternate ribs and grooves, a, liquid medium disposedwithin said grooves, whereby deformation of said rubber member bymovement of said piston toward said end of the housing will causedisplacement of the liquid medium within said grooves, said ribsconstituting flexible packing rings for obstructing the flow of saidliquid medium.

CURT SAURER.

